Biodieseling a Ponton

[anthology]

I just joined the DC Biodiesel Co-op and now, I need a diesel to supplement my old gas-guzzling LC FJ60.

I'm looking to get a 190d Ponton, but B100 degrades old rubber fuel lines. Anyone upgraded one to run bio, and what size/length of hose was required? I'm assuming it'd have to be viton, but do you get this from a dealer or would somewhere like McMaster-Carr do?

I'd like to have all the parts necessary beforehand.

[R Leo]

Pre 1995 cars have Buna-N or natural rubber components in their fuel systems. Some of these parts (fuel supply and return lines) can be replaced using viton tubing by the average DIYer. Pre-'95 diesel injection pumps also have internal Buna-N components (o-rings) that will be degraded by B-100; unfortunately, those parts generally aren't DIY replacable.

The better thing to do would be blend B100 with either diesel, or SVO to a maximum 20% concentration (ie B20). B20 is generally accepted as the maximum concentration of biodiesel for reliable operation in older (Buna-N, nitrile and natural rubber) vehicles.

More info here and here.

[anthology]

I just read your links and it appears one MAY be able to get the injectors rebuilt with newer materials that wouldn't degrade? Of course this costs and requires some work, but it seems feasible.

I could start with B20 and get the injectors rebuilt when there's some winter downtime.

Lots of good info there...looking to learn more. Do you have a source for parts and replacements like fuel and oil filters for older MBs?

[tomm9298]

YES!!!! Most parts are available on this forum.... Just click on FastLane link at top of page....... you're there!!!

[R Leo]

Originally Posted by anthology

I just read your links and it appears one MAY be able to get the injectors rebuilt with newer materials that wouldn't degrade? Of course this costs and requires some work, but it seems feasible.

The injectors aren't the problem; there aren't any rubber seals in them. The injection pump (IP) is the primary issue since there is at least one o-ring in the IP at the throttle shaft. I'm not sure how many other rubber/nitrile components are involved in the IP but I have a Bosch technical book on order that hopefully, will enlighten me.

[anthology]

In a way, that is more helpful in that it "should" be fairly straightforward. I have a mechanic closeby that deals specifically in old MB, as well as diesels. I've yet to ask about this process. I'm sure they'd be inquisitive.

Keep us informed of your findings when the manual arrives. Thanks.

BTW, how do all these folks with 300d's and td's run B100 with no problems? Is there something they're not telling me?

[Alan Hamm]

Originally Posted by anthology

I just joined the DC Biodiesel Co-op

Tell me more, tell me more. A DC Bio-diesel Co-op?

[R Leo]

BTW, how do all these folks with 300d's and td's run B100 with no problems? Is there something they're not telling me?

Offhand, I don't know of anyone on this board having run straight biodiesel in a 123 or earlier diesel Benz without encountering filter clogging or fuel line leakage at some point. I could be wrong.

IIRC, most Forumites are running blends of bio/diesel, WVO/diesel or bio/WVO.

[RLD]

I did some digging around on this awhile back and from what I remember, all of the new replacement parts, seals etc from bosch for old diesels are supposed to now be compatible with biodiesel due to some european regulations.

----------Robert

[Alan Hamm]

Are the issues the same with WVO?

[R Leo]

Originally Posted by Alan Hamm

Are the issues the same with WVO?

No, degradation of nitrile and rubber is associated with high concentrations of methylated esters (biodiesel). WVO is not methylated.

Biodiesel distributors and the biofuel crowd recommend keeping the mixture to a level of B20 or less on pre-95 vehicles to avoid problems.

[anthology]

Originally Posted by Alan Hamm

Are the issues the same with WVO?

WVO has to be filtered, then heated in some way before it gets to the injectors. I hear they get coked up though.

The DC Biodiesel Co-op can be found here: http://finance.groups.yahoo.com/group/DCBiodieselcoop/

Looking to make some large bulk purchases come spring.

[R Leo]

Originally Posted by anthology

WVO has to be filtered, then heated in some way before it gets to the injectors. I hear they get coked up though.

Sure WVO has to be filtered, but the stuff is damned near free and around here, B100 is $3.40/gallon and diesel is in the $1.90-2.05 range. Worth the effort and trouble, I think. Using WFO also makes a subtle political statement.

Heating WVO? Maybe for pumping from the vehicle tank, but I'm not so sure about the necessity of heating for proper injection and reduced coking. Here's why: a running engine conducts a fair amount of heat into the injector body...my non-contact thermometer indicates ~200°F when aimed right at the point where the injector screws into the precombustion chamber and, enough heat is conducted into the high pressure supply line to maintain a 150° to 170°F temp in the line.

So, even at full chat with a lot of oil passing through the supply lines, there's certainly enough energy to heat that small volume of oil to +150°F before it is injected. I will be adding fuel heaters and a boost pump to the cars but that is only for pushing clouded oil to the IP prior to getting the engine up to temp.

My wagon had about 2000-3000 miles on a set of freshly rebuilt injectors when I changed to running a WVO/biodiesel blend. My plan is to continue running the WVO blend (when the temps drop I may have go to a 70% WVO/30% diesel blend to lower the oil's cloud point) to about 10,000 miles. At that time, I'll pull the injectors and analyze their condition.

[anthology]

Originally Posted by R Leo

Sure WVO has to be filtered, but the stuff is damned near free and around here, B100 is $3.40/gallon and diesel is in the $1.90-2.05 range. Worth the effort and trouble, I think. Using WFO also makes a subtle political statement.

Heating WVO? Maybe for pumping from the vehicle tank, but I'm not so sure about the necessity of heating for proper injection and reduced coking. Here's why: a running engine conducts a fair amount of heat into the injector body...my non-contact thermometer indicates ~200°F when aimed right at the point where the injector screws into the precombustion chamber and, enough heat is conducted into the high pressure supply line to maintain a 150° to 170°F temp in the line.

I was always under the impression that WVO clogged the injectors, burned incompletely, and was overall, just a mess to deal with. Of course, it is free (or nearly so) and that's a major plus, as well as the fact diesels can run satisfactorily off of them, just didn't know it was very healthy for the engine. Then I think there is the whole 'scavenging' aspect and percieved difficulty in its use on a regular basis. For a DIY'er, none of this poses a problem. Get into the real world, with regular people that want to pump and go and you open a new can of worms.

In your current setup, does the oil cloud so easily (or often) that a heater would be required to even get it from the tank? That would be my worry. The whole 'wire/plumb it up to switch tanks' would be a hassle for me. That is why I asked about B100 because it is locally available and I wouldn't have to go through the pouring and filtering etc.